Computed Tomographic and Pathological Features of Primary Pulmonary Sarcomatoid Carcinoma.

OBJECTIVE: To investigate the computed tomographic (CT) and pathological features of primary pulmonary sarcomatoid carcinoma (PSC).

METHODS: The clinical data and CT images of 20 patients with pathologically confirmed PSC were retrospectively analyzed.

RESULTS: Solitary pulmonary mass was identified in 18 patients and multiple pulmonary masses in 2 patients, amounting to 22 masses. There were 17 peripheral masses and 5 central masses, including 11 masses larger than 5 cm. The smooth margin was identified in 9 masses, deep lobulation and/or spinous protuberance in 11 masses, and ill-defined margin in 2 masses. Pleural indentation was identified in 2 masses and pleural thickening with wide basement was identified in 14 masses. On plain CT, cavity was observed in 5 masses, hypo-density in 7 masses, and homogeneous density in 10 masses. On contrast-enhanced CT scanning, irregular ring/patchy enhancement were shown in 15 masses and slightly homogenous enhancement in 2 masses. Of all patients, 6 patients had unilateral or bilateral hilar and/or mediastinal lymphadenopathy. There were 16 pleomorphic carcinomas and 4 spindle cell carcinomas. Immunohistochemically, anti-pan cytokeratin antibody was positive in 13 patients, cytokeratin was positive in 8 patients, Vimentin was positive in 15 patients, epithelial membrane antigen was positive in 1 patient, and thyroid transcription factor-1 was positive in 8 patients.

CONCLUSION: PSC has some specific CT features; however, the final confirmation of PSC still depends on pathological and immunohistochemical examinations.